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1987 S10 Needs help!! Engine? Possible Trans issues

10-30-2009, 05:04 PM
I have a 1987 Chevrolet S-10. It has the 2.5 inline 4 cylinder, with a 4 speed manual transmission. Its a truck I am in the process of rebuilding, and a learning process in and of its own. I replaced the valve cover gasket, put in new plugs, distributor and rotor. The timing was way off when I bought the truck, it was at 0 degree BTC, its supposed to be at 8 degree BTC. I just got it back from the shop where I had timing done. The timing in and of itself seams to be fine, however, the engine does not idle properly, fluctuates heavily. Motor will stall out, I dont really drive it. I'm trying to figure out if the motor is junk, if I need to have it rebuilt or swapped. It runs weak, and not having a tachometer in the vehicle I dont know if its just an old loud engine with a slipping clutch. I guess perhaps I'll just drive it and see, the last time I did a clutch it went from fine to gone in three days, 70 miles. I doubt this beast will make it to 55 mph. I am at a loss, I just want to find the problem, fix it, so I can finnish with the rest of my cosmetic repairs. I have replaced front calipers, rear drums shoes hardware kit, all break lines, only thing in the break system left is master cylinder and break booster. New shocks. Its ugly, I just cant seam to figure out why its running weak. Trans feels good, but with as little power going to it who knows at this point. Any help would be much appreciated.:smokin:

10-31-2009, 03:30 PM
Start with a compression check.
Got any blow by or engine smoking burning oil or overheating?

11-01-2009, 11:06 AM
No blow off or leaks, aside from clutch line which I will get to in a sec. Had leak from valve cover, the idiot that put the old one on was lazy and tied the gasket to the valve cover with binding wire so he could line it up which in turn sliced the valve gasket. Fixed that torqued nuts to specs, no engine leaks or smoke aside from the exhaust, I believe its running rich, start it up in five minutes there will be a puddle by the exhaust pipe, no fuel in it fortunatly. No fluids are mixed, ie. oil and coolant. The rubber line that goes from the cab to the slave cylinder is all cracked and I need to replace it, however the clutch works, but I am not driving it at all untill I get that hose. Without having a tachometer I dont know if the clutch is slipping until I veryfy compression. If the engine needs much works I will probably just find a different drivetrain with less miles, dont know how many are on it. The speedometer was out when I purchased the truck, replaced the cable which was rusted inhalf, the guage works, but I believe it is speedometer sensor. Thats the last thing I am worried about at the moment.

11-01-2009, 04:42 PM
If compression is good and no blow by or oil smoking you may be able to sve it.
Check for codes and post back if any codes.

11-03-2009, 12:19 PM
Well I am still trying to get ahold of my friend to borrow his compression guages. As I said it was just timed. The timing seamed good when I got it back from the shop. Started it up and it seams that the timing is starting to revert back, and the check engine lights on now. As soon as I can check compression, which I am pretty sure is off, I'll go from there I guess.

11-03-2009, 12:22 PM
Pull codes and see why check engine light is on.
Post back codes.

11-03-2009, 09:00 PM
Alright, still never got ahold of the compression guage, however I did pull the codes. The only thing I got aside from code 12 which flashed 1 pause then twice is code 42, which is 4 flash pause 2 flash. Book says thats electronic spark timing EST which makes sence to me givin the ongoing problem I have been trying to fix. It says possibly an HEI module. I'll price them tomorrow. Like I said the only thing leaking is the clutch line with will be fixed b4 this thing hits the road but thats not gunna effect the engine correct? Not sure if I had posted it, it was just timed at a shop, have new distributor and rotor, new plugs, haven't done the wires yet but they appear to be fine. Thanks so much for quick responses.

11-03-2009, 09:33 PM
O few things I may have forgot, I did replace the o2 sensor already. The previous owner had the exhaust hacked to all hell, and had removed the cat. The exhaust is fixed but no cat. If you put your hand over the exhaust pipe for about 10 - 15 seconds, your hand will be rather wet.

12-20-2009, 10:40 PM
There is water vapor as a byproduct of combustion. Hence the moisture. Check the EGR, they are notorious for giving issues on these dukes. s10forum has a 2.5l section with all kinds of info on this engine. the duke was also used in the fieros and there are some mods/ etc some have found from there.

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